Electric drill system



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P ItentedJune 10, 1890:

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UNITED STATES HARRY N. MARVIN, OF SYRACUSE, NEIV YORK.

' ELECTRIC DRILL SYSTEM.

SPECIFICATION forming part of Letters Patent No. 429,731, dated June 10,1890.

Application filed March 19, 1890 ing is a specification, reference beinghad to the drawing accompanying and forming a part of the same.

This invention is an improvement applicable to a system or plan ofoperating percussion or reciprocating drills and similar tools, in whichpulsations or impulses of current are directed in alternation from asuitable generator or source of current through oppositelyacting coils,which effectthe reciprocation of a magnetic core to which thedrilling-tool is connected. Such devices or tools are used in mines,quarries, and the like, and frequently at a considerable distance fromthe generator or source of current. Under such circumstances it is oftendesirable to use a line-current of higher potential than that used inthe drills, and under other circumstances it is often desirable toconvert a continuous current into one that is better adapted to elfectthe operation of the drills.

The subject of my present invention is an apparatus by the useof whicheither of these results may be accomplished.

Generally stated, it consists in a transformer adapted to convert director continuous currents of a given potential into pulsating currents ofthe same or another potential, which is to be connected at any desiredpoint in an electric circuit, and which may be used to operate one orany desired number-of reciprocating drills.

The general plan of construction of this device is an armature,preferablyof cylindrical or annular form, mounted to turn between properfield-magnets and provided with two windings. One of these windings,which may be regarded as the primary, inasmuch as it is to be connectedto the line or generator circuit, is provided with a commutator andbrushes by means of which the line-current imparts rotation to saidarmature. The other winding is connected to any suitable form of currentdistributor or commutator by means of which current impulses,pulsations, or al- Serial No; 344,482. (No model.)

tion'of the secondary winding in the magnetic field produced by theprimary current. The details of this invention will be under stood byreference to the accompanying drawing,whi ch is a view, partlydiagrammatic and in perspective, of an apparatus constructed inaccordance with the invention.

l/Vhat I designate as the transformer in this case comprises practicallya motor and a generator, the former being adapted to be operated by acurrent from a suitable source and the latter being constructed tosupply defined impulses or pulsations of current. Such a device may beconstructed in various ways; but that which I prefer is constructed asfollows:

A is an armature-shaft, on which is mounted a suitable armature-corethat is capable of revolving in the field produced by magnets.(Represented by 13.) The core is wound with two independent coilsor-set-s of coils. (Designated by the letters 0 and D, respectively.) Atone end of the core is an ordinary segmental commutator E, with theplates of which the coils or loops from the coils C are connected.Brushes F bear 011 this commutator and are adapted to be connected withthe line-wires from any suitable source of continuous currents. I haveomitted to show any of the ordinary provisions for exciting thefield-magnets from the main line, as this is a matter well understood.There is a second commutator G at the opposite end of the core, and tothe plates of said commutator the secondary coil or coils D areconnected in the usual manner.

In addition to the commutator G there are secured to the shaft A twodisks II I. One of these disks, as II, is provided with a metal ring J,connected with a segment or plate of the commutator, and the other, asI, carries ahalf-ring K, connected with the diametrically-oppositecommutator-segment. A single brush L bears on the continuous ring J, andtwo brushes M N bear upon opposite sides of the edge of the disk I.

5 The drill is represented by O, and its two coils are shown asconnected by one of their terminals to the brushes M N, respectively,while theot-her terminals are joined by a common return-wire to thebrush L.

It is apparent from the character of this construction that a continuouscurrent directed through the coils G will impart rotation to thearmature, and that in consequence current will be developed in the coilor coils D, and that this current will be delivered in impulses ofrising and falling potential alternately into the two circuits of thedrill. Atthe same time a secondary continuous current may be taken offfrom the commutator G by brushes P R bearing thereon.

The commutator G may be dispensed with and the coil D connected directlyto a suitable form of distributer for delivering current impulsesalternately to the drill-coils, or any other form of distribntersuitable for this purpose may be used in conjunction with thecommutator. I do not describe in detail any of the various forms ofdistributer that may be used in this way, as I have shown several ofsuch devices in my Patent No. 420,816, dated February 4, 1890, andelsewhere, and they are now well understood.

Vith this plant all the advantages of a converter system may be secured,while a ready and practicable means is provided for operating my drillsfrom any continuous-cur rent circuit.

The invention claimed in this application is limited to combinationsinvolving the use of a transformer, and the broad principle of operatingdrills by pulsating or alternating currents is not claimed herein.

What I claim is 1. A transformer for electrically-reciprocated drillsystems, comprising, in combination, motor-coils and generator-coilsmounted to rotate in the same field of force, a commutator connectedwith the motor-coils, and a distributer connected to the generator-coilsand adapted to connect said coils alternately with the drill circuits orcoils, as herein set forth.

2. The combination, with field-magnets, of an armature-core mounted torotate within the field of force produced thereby, primary and secondarycoils wound on said core, a commutator connected with the'prim'arycoils, a distributer composed of a continuous and a half ring connected,respectively, to opposite points or parts of the secondary coil, and

brushes forming the terminals of two independent circuits bearing uponthe said rings in the manner described.

HARRY N. MARVIN.

\Vitnesses:

A. A. SCHENCK, G. WV. TACKABURY.

